A new study evaluating models of future climate scenarios has led to the creation of the new risk categories “catastrophic” and “unknown” to characterize the range of threats posed by rapid global warming. Researchers propose that unknown risks imply existential threats to the survival of humanity.

Researchers projected warming scenarios that vary based on what societal actions are taken to reduce emissions. CREDIT Scripps Institution of Oceanography at UC San Diego

These categories describe two low-probability but statistically significant scenarios that could play out by century’s end, in a new study by Veerabhadran Ramanathan, a distinguished professor of climate and atmospheric sciences at Scripps Institution of Oceanography at the University of California San Diego, and his former Scripps graduate student Yangyang Xu, now an assistant professor at Texas A&M University.

The risk assessment stems from the objective stated in the 2015 Paris Agreement regarding climate change that society keep average global temperatures “well below” a 2°C (3.6°F) increase from what they were before the Industrial Revolution.

Even if that objective is met, a global temperature increase of 1.5°C (2.7°F) is still categorized as “dangerous,” meaning it could create substantial damage to human and natural systems. A temperature increase greater than 3°C (5.4°F) could lead to what the researchers term “catastrophic” effects, and an increase greater than 5°C (9°F) could lead to “unknown” consequences which they describe as beyond catastrophic including potentially existential threats. The specter of existential threats is raised to reflect the grave risks to human health and species extinction from warming beyond 5° C, which has not been experienced for at least the past 20 million years.

The scientists term warming probability of five percent or less as a “low-probability high-impact” scenario and assess such scenarios in the analysis “Well Below 2°C: Mitigation strategies for avoiding dangerous to catastrophic climate changes,” which will appear in the journal Proceedings of the National Academy of Sciences on Sept. 14.

Ramanathan and Xu also describe three strategies for preventing the gravest threats from taking place.

“When we say five percent-probability high-impact event, people may dismiss it as small but it is equivalent to a one-in-20 chance the plane you are about to board will crash,” said Ramanathan. “We would never get on that plane with a one-in-20 chance of it coming down but we are willing to send our children and grandchildren on that plane.”

The researchers defined the risk categories based on guidelines established by the Intergovernmental Panel on Climate Change (IPCC) and previous independent studies. “Dangerous” global warming includes consequences such as increased risk of extreme weather and climate events ranging from more intense heat waves, hurricanes, and floods, to prolonged droughts. Planetary warming between 3°C and 5°C could trigger what scientists term “tipping points” such as the collapse of the West Antarctic Ice Sheet and subsequent global sea-level rise, and the dieback of the Amazon rainforest. In human systems, catastrophic climate change is marked by deadly heat waves becoming commonplace, exposing over 7 billion people to heat related mortalities and famine becoming widespread. Furthermore, the changes will be too rapid for most to adapt to, particularly the less affluent, said Ramanathan.

Risk assessments of global temperature rise greater than 5°C have not been undertaken by the IPCC. Ramanathan and Xu named this category “unknown??” with the question marks acknowledging the “subjective nature of our deduction.” The existential threats could include species extinctions and major threats to human water and food supplies in addition to the health risks posed by exposing over 7 billion people worldwide to deadly heat.

With these scenarios in mind, the researchers identified what measures can be taken to slow the rate of global warming to avoid the worst consequences, particularly the low-probability high-impact events. Aggressive measures to curtail the use of fossil fuels and emissions of so-called short-lived climate pollutants such as soot, methane and HFCs would need to be accompanied by active efforts to extract CO2 from the air and sequester it before it can be emitted. It would take all three efforts to meet the Paris Agreement goal to which countries agreed at a landmark United Nations climate conference in Nov 2015.

Xu and Ramanathan point out that the goal is attainable. Global CO2 emissions had grown at a rate of 2.9 percent per year between 2000 and 2011, but had slowed to a near-zero growth rate by 2015. They credited drops in CO2 emissions from the United States and China as the primary drivers of the trend. Increases in production of renewable energy, especially wind and solar power, have also bent the curve of emissions trends downward. Other studies have estimated that there was by 2015 enough renewable energy capacity to meet nearly 24 percent of global electricity demand.

Short-lived climate pollutants are so called because even though they warm the planet more efficiently than carbon dioxide, they only remain in the atmosphere for a period of weeks to roughly a decade whereas carbon dioxide molecules remain in the atmosphere for a century or more. The authors also note that most of the technologies needed to drastically curb emissions of short-lived climate pollutants already exist and are in use in much of the developed world. They range from cleaner diesel engines to methane-capture infrastructure.

“While these are encouraging signs, aggressive policies will still be required to achieve carbon neutrality and climate stability,” the authors wrote.

The release of the study coincides with the start of Climate Week NYC in New York, a summit of business and government leaders to highlight global climate action. Ramanathan and colleagues will deliver a complementary report detailing the “three-lever” mitigation strategy of emissions control and carbon sequestration on Sept. 18 at the United Nations. That report was produced by the Committee to Prevent Extreme Climate Change, chaired by Ramanathan, Nobel Prize winner Mario Molina of UC San Diego, and Durwood Zaelke, who leads an advocacy organization, the Institute for Governance and Sustainable Development, with 30 experts from around the world including China and India.

At this point in the debate Gold, we need to think of them as contrarians. There was a time not so long ago they were the dominant political position. Now, not so much?

It’s our moral and scientific duty to take them seriously and understand the arguments they set forth.

As Anthony rightfully informs us, the probabilities the alarmist camp is correct in their evaluation is low, but it isn’t zero. We must allow for the argument and carefully evaluate the evidence they provide. Anything less wouldn’t be scientific.

If the AGW’ers reallly believed in what they are saying, they would be moving to northern BC, Alaska, Northwest Territories, Nunivat, Northern Scandinavia, Mongolia and Siberia.

But they are not. Al Gore and Leonardo should long ago have abandoned So Cal, but they haven”t. Obama is negotiating a Hawaii property deal. Even Steven Mosher says, “I like living in California,” when if he believed in AGW he should have invested in Prince Rupert or Anchorage.

I, for one, took advantage of this silliness and bought real estate in Southern CA on the belief both Al and Leo were wrong. I voted with my feet.

There’s a lot to be said for a warm climate in a mostly agricultural area. I liked the odds so I moved in with the people who grow grapes in San Louis Obispo county. Color me stupid! Property doubled since then. Who would have guessed?

You folks keep buying land in Alaska. I’ve sold mine already so don’t let me slow you down :)

What was the temperature during the Medieval Warm period? the Roman? the Minoan? the Holocene Climatic Optimum? As the probable range of temperatures for those non-catastrophic periods is above the dread 2 degree rise, I discount the predicted catastrophic scenarios.

Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don’t know we don’t know… it is the latter category that tend to be the difficult ones.
Donald Rumsfeld

You might want to google Dr. Malcolm Kendrick. His opinions on Ancel Keys can barely be published. He has written, I think, two books on the scourge to humanity that is Statins and has a continuing newsletter about what causes Coronary Heart Disease, which is contrary to conventional science. He also did a calculation demonstrating that statins were potentially the most profitable drug ever conceived, running into Trillions of £/$. The scam was getting into climate change proportions. Fortunately, it seems the drugs companies have been rumbled.

Folks here may think this is getting off-topic for a climate site but I don’t actually think so. I also have read Dr Kendrick (a practising Scottish doctor) from a gift from my brother (who concurs with Kendrick after a full career in general practice in our wretched NHS). “Follow the money” is a great clue to all manner of pseudo-scientific scams and the “great cholesterol con” (Kendrick’s book) has a close analogy with CAGW in this respect. And of course left/liberal politics and media relentlessly promote statins, low “cholesterol” (actually it isn’t cholesterol – read Kendrick) etc as the only way forward in healthcare.

During my career stints in the Land of The Free I also noticed a related phenomenon over the “Atkins diet” from casually reading left/liberal newspapers like the NYT. Atkins’ message was basically “fats don’t make you fat, carbs do” and demonstrated his theory by being just about the only medical practitioner with demonstrated success at treating American standards of morbid obesity. Faced with (so-called: read Kendrick again) “hyper-triglyceridaemia” I tried it on myself. It worked. But the liberals of the NYT were furious – “irresponsible, wrong”, “health science denier” (actually they didn’t think of that one then, but might have done).

What’s the common thread ? Not sure I can wholly put my finger on it, but “science” has a basically high social standing, especially in the US, so people like to be thought of as “scientific” in their general outlook. Hence “climate science denier” etc. But they aren’t, because in all three examples, the left/liberal media (why do they latch onto these things ?) are themselves “in denial” about looking at basic empirical facts. Does the Atkins diet treat morbid obesity, hypertriglyceridaemia etc successfully, or not ? Does artificially lowered blood serum “cholesterol” reduce growth of atherosclerotic plaques, or not ? Does increased CO2 *cause* increased global temperature (or hurricanes, or whatever), or not ?

In the cholesterol and climate cases, the alarmists have the advantage of a tsunami of fancy publications, bulging with flaky data dressed up to look rigorous, readily available only to professionals whose libraries pay the journal subscriptions. And the spare time to plough through the stuff. They also have cheerleading squads who distort what could (in principle) be properly stated as a properly testable, falsifiable, scientific theory (and being ready to accept the verdict of experiment) into patently unfalsifiable “theories” that (in Clive James’ already immortal phrase) “no fact doesn’t fit”.

“HotScot” got me going because he’s spotted the same thing as me: “narratives” that everyone is supposed to believe (it’s settled science after all, 97% of scientists agree etc) and yet if you take the trouble to look into it, the “narrative” starts to crumble, all the while its defenders get angrier and nastier.

I am posting these rambling thoughts in case someone more insightful than I has observations from other such “social representations” that might help understand the ugly politics of CAGW.

Give this one a read if you haven’t already. I think it explains much about how and why there is such a stark division of opinion on CAGW as well as just about any topic of any kind — scientific or otherwise — that becomes a partisan political issue: In there somewhere there may be a few hints about why Lord Keynes’ “multiplier” has enjoyed such a long but unsuccessful life…..and is still living a life of declining success in that strange little foreign country that’s called The District of Columbia.

Yes, but those earlier warm periods were natural, not unnatural, which is key because there’s a huge difference between sitting in 87 F naturally and being at 87 F artificially. One means that your on a Florida beach sipping a Corona, and the other means your psychotic mother-in-law is playing with the thermostat again.

Have these guys actually predicted anything that has come to pass? Where’s the evidence of temp related droughts, floods, hurricanes, etc.We know there has been no correlation after a century and a half of warming. Why do they think it will suddenly appear? And why are they promoting crappy renewable energy to redcue CO2?

Australia’s own Tim Flannery predicted:
1. That the dams in Queensland, New South Wales and Victoria would never be full again. Shortly afterwards, down came the rain and, lo, they were full.
2. He also predicted that Perth, Western Australia would become the first ghost city of the 21st century because of increasingly dry climate. Since his prediction the population of Perth has grown substantially.

Imagine this:-
Camera zooms in on an ant until it fills the screen, its MASSIVE JAWS flexing threateningly and then an authoritive voiceover says “DEADLY MONSTERS FROM MARS WILL DEVOUR EVERY HUMAN ON THE PLANET WITHOUT MERCY IF THEY ARRIVE AS SCIENCE EXPERTS FEAR”.
Yawn, yeah, yeah, same old same old, seen and hear it all before. This is just life imitating art. In this case the ‘life’ is CAGW and the ‘art’ is Orson Wells broadcast of ‘War of the Worlds’ in 1938.
Clever graphics though, working in EXISTENTIAL THREAT like that. Clever marketing I have to admit. Typically fraudulent but clever in a slimy, deceptive, dishonest, amoral kinda way.

I wondered that (because “strong” verbs are an old and mostly closed set) and ended up this piece of information:

Shat is a humorous past tense form, not etymological, first recorded 18c.

Also other sources state it is ‘widely accepted’ and formed using sit-sat-sat as a model. ‘to shit’ is derived from the Indo-European root *skei that means ‘to cut’ and is a cousin to the word ‘science’. Funny that.

See Forrest Gardner, to dial the knobs to 12 or 13 you have to step beyond the earth itself. Like solar system-wide catastrophe or galactic catastrophe or best yet, universal catastrophe. The implications, of course, are that unchecked human expansion and use of pollutants would have a negative effect on the galaxy as a whole.

Here’s the way you would use it. “Humans need to stay on the Earth. If they are allowed to spread their CO2 to other planets, it would be a galactic catastrophe”. See, its beautiful. It implies that humans are cockroaches and CO2 is our excrement.

It now seems the Aussie government is questioning the practicalities of all that wind power that’s screwing up their grid and proposing, quite sensibly, a cheap, stable baseload which is, of course, coal.

In the UK, a government document was photographed on a train when an indiscreet official was reading it. Seemingly, the dial is about to be turned down on climate change and EU targets dumped when the spectre of fines is gone after Brexit.

Meantime, everyone seems to be avoiding the much greater Existential Threat posed by a rolly-poly lump of shit in N. Korea …. get real, folks, and focus on The REAL THREATS with a MUCH higher probability of realization.

The Glorious Guiding Son of North Korea has undertaken tremendous measures to limit CO2 emissions, such as allowing almost no cars, tractors, or civilian air transport, and keeping all the lights off at night.

By the way, just from looking at him it’s pretty easy to tell that Kim Jung Un has Cushing’s syndrome from too much cortisol. The moon face is a dead giveaway.

““Dangerous” global warming includes consequences such as increased risk of extreme weather and climate events ranging from more intense heat waves, hurricanes, and floods, to prolonged droughts. Planetary warming between 3°C and 5°C could trigger what scientists term “tipping points” such as the collapse of the West Antarctic Ice Sheet and subsequent global sea-level rise, and the dieback of the Amazon rainforest. In human systems, catastrophic climate change is marked by deadly heat waves becoming commonplace”

One wonders which universities study and teach the science of “catastrophe” and “catastrophe causes”?

Making this research all about alarmism, inciting fear and preying on civilians.

Catastrophe theory originated with the work of the French mathematician René Thom in the 1960s, and became very popular due to the efforts of Christopher Zeeman in the 1970s. But, it’s not very popular now. Maybe the climate catastrophists should resurrect it.

1) The warming so far has been seriously over estimated by adjusting data (so called in some cases) to change inconvenient trends that previously wasn’t shown.
2) Reducing cooling historic periods increases the warming difference between past and present.
3) Non-existent additional warming by using the above tricks in 1) & 2), doesn’t actually warm the planet further, so humans not noticing any local changes only confirms this.
4) No optimum warm period during an inter-glacial over the last few millions years has ever got chance to go above about 3 c warmer than today.
5) There is no scientific evidence that an increase between 1.5 c and 3 c is dangerous as suggested in this article.
6) Any increase above 3 c is so far fetched and against scientific knowledge, it is no different to the man holding the end of world sign up in the street.
7) The modelers don’t have a clue how temperatures this warm could happen because the mechanism/method would be able to be demonstrated by other means.
8) They don’t have a clue how the pause occurred and are still trying to deny it ever happened.
9) Global temperatures are actually warming no more than roughly 1 c per doubling of CO2 with no positive feedback demonstrated.
10) Point 4 provides evidence something prevented further warming and the likely cause was negative feedback towards the other direction.

Proxies show whenever there were high temperatures with high CO2 levels, cooling soon followed and CO2 levels declined with them about 800 years later. Therefore with the current position of continental land masses any warming would likely be restricted by negative feedback. Global temperatures have been much warmer than 3 c today, but many million years ago the oceans and continents were much different. The models have no idea how this negative feedback behaves, so can’t be demonstrated on future scenarios or the pause. Additional CO2 won’t change these natural observations from noise because it is an effect, not cause. Water vapor has by far the biggest affect on climate, not just to it’s greenhouse like nature, but because it especially decreases dust levels in the atmosphere.

Yes, Matt, the presence of water vapor during the ice ages alone is enough to falsify agw theory. The difference between glacial and interglacial is only about 5C globally. Water vapor far outstrips co2 as a greenhouse gas. After all the warming done by water vapor, there is not much room for warming from co2. (then consider m cycles, albedo and that mysterious “something” in your point 10, too)…

There is a relationship between wv and ANY warming. Since warming from wv is proportionately much greater than co2, than the wv positive feedback loop is also proportionately greater than wv feedback from co2…

Why aren’t the AGW proponents concerned about the increase in man-made reservoirs, lawn sprinklers, and these large center pivot irrigation sprinklers used to water thousands of acres of formerly arid land? Surely this would have just as much warming effect as CO2.

Good points Matt. If they say at one point (years back) that 2 C increase is bad but then cool the past, that is not an actual increase that should count toward their original “dangerous” temperature. And are they saying that 1.5 C over the next 30 years could be an existential threat or are they saying an additional 0.3 to 0.7 degrees (given that they think temps since 1880 have gone up 0.8 to 1.2 C) could be very dangerous? 0.3 over the next 30 years as very dangerous is obviously ludicrous but in most claims like this they don’t make it clear that half of the 1.5 to 2 C has already happened.

When the starting point occurs does make a significant difference to the claims. I have not been able to find this paper so far, but a recent one by the same author shows this below. Some papers refer to this starting point from the start of the industrial era, but they do vary and the one below shows after the year 1900. The 2c increase being bad only came about recently, when they realised this range was more likely than the 4.5c range.

If the claims of this paper are similar to one earlier (2016), then it looks like 2 c after the year 1900 is apparently bad. This point is a cherry pick because previous decade(s) were warmer. Therefore the authors are saying the planet’s climate will be bad with another 1c rise.

I’mma just sayin, this Michigan summer was one of the most pleasant that I’ve experienced in a while… been living in Alabama and West Virginia for the last few years, Michigan weather beats every other state hands down… peas.

“…The release of the study coincides with the start of Climate Week NYC…”
Wow, what are the odds of THAT happening! No convenient political timing here, we swear! No sir, this was -strictly- about the Science!

Almost all of these warnings about the risk of future warming emphasize the why humans should change energy sources and a bit on the how (substitute renewables for fossil fuels). But they fail to evaluate what’s involved in fully accomplishing the how. IF reliable and affordable energy is not maintained during such changes (and now it cannot be), then the world economy will experience an existential threat of a different kind.

“Global CO2 emissions had grown at a rate of 2.9 percent per year between 2000 and 2011, but had slowed to a near-zero growth rate by 2015. They credited drops in CO2 emissions from the United States and China as the primary drivers of the trend.”

According to NOAA (ESRL), Mauna Loa shows no such slow down, does it take time to show up in actual readings, or is the slow down in CO2 production only ‘on paper’ – ie manipulated?

When a layperson with little to no scientific background, like the news media, read such studies they end up believing, and then trying to tell us, that all this will happen suddenly, not over hundreds of years, if it happens at all. Nor do such studies even suggest how if greenhouse gases are so terrible we get China and India to reduce just their growth rate in producing such gases. Why does China and India have such a different view of all this? Could it be their long recorded histories tell a different story than our AGW crowd is trying to tell us in the developed countries. Here is a question to ponder. If humans are the worse thing to happen to earth why do the environmentalists care if we are wiped out by CAGW?

How will they live in the finest houses, eat the finest foods and drink the finest wines if the grant money is gone because the working people who fund their lifestyles are dead?

How will they gather together to congratulate themselves on their moral and intellectual superiority in saving the planet from we the dirty, unwashed, intellectually inferior masses of humanity who dared to suggest that they, even they themselves, should offer a modicum of proof for their propositions if they are dead?

Ramanathan, a lead author in IPCC’s Special Report on Emissions Scenarios, has been an over-the-top climate scare forecaster since at least 1988 and has been using the phrase “existential threat” for some time. The problem is that all of these Emissions Scenarios are based on climate response to cumulative emissions and the use of cumulative emissions inserts a fatal statistics error into the forecast of “future climate scenarios”. I may have posted the link for my work on cumulative emissions on WUWT before but here it is again as a response to your Ramanathan post. Thank you for this forum.https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3000932

Even if they are thrilled at the prospect of humans becoming extinct, they still have to earn a living in the meantime. Nothing is more dependable for securing money for researchers than alarming the public.

That means there is a 19-in-20 chance of no significant damage or an improvement in the climate by 2050. But the “or worse” part of that sentence has me curious. What could be worse than “catastrophic” damage? To me, even the destruction of the entire planet would be a catastrophe. They make a later reference to it being “beyond catastrophic.” What does that even mean? Is there an adjective worse than ‘catastrophic’?

“Researchers propose that unknown risks imply existential threats to the survival of humanity.”

How do you falsify a conclusion like that? In fact, how can you even determine whether something “unknown” will be a risk or a benefit to human survival? Contact with aliens, for example, could result in our total destruction. Or they might take pity on us and give us a cure for cancer, or give us the technology for a Star-Trek-type replicator that could be a boon to humanity. Global warming could be similar. It could cause us harm or it could be a net benefit to the planet like it has been since the last ice age. There are just too many unknowns to say for sure. But what good does it do to even worry about ‘unknown’ risks? We could be wiped out by an asteroid or by the radiation of a nearby supernova before we even get to 2050. If a risk is truly unknown, there is nothing we can do about it. There are plenty of ‘known’ risks for us to worry about.

The climate change we have been experiencing is caused by the sun and the oceans over which Mankind has no control. The models are unsubstantiated fiction hence their results are nothing more than some form of Science fiction. One can safely conclude that if the sun undergoes a super nova and the Earth is vaporized, man made climate change will no longer be an issue.

These people really don’t understand the difference between 1 in 20 of their model runs showing “catastrophic” damage, and the actual probability in the real world of such damage….or worse! Catastrophic is not scary enough obviously.

Any school pumping out such drivel obviously has way too much taxpayer funding to waste. When is the market for this “work” going to finally dry up?

If, as they say, we can expect the climate to be a few degrees warmer, it would still be cooler than the current climate conditions in Singapore (daily maximum temperature of around 30 deg C year round).

Prominently and up front is a diagram that is supposed to explain everything:
If we look at the last curve in dotted line they explain everything
BL (CI – 80% & C feedback). They explain that BL beans baseline (whatever baseline they mean is not explained). Then CI – 80%?

What does CI mean?

From the free encyclopedia: The term is usually used within the law enforcement world, where they are officially known as confidential or criminal informants (CI), and can often refer pejoratively to the supply of information without the consent of the other parties with the intent of malicious, personal or financial gain.

This “existential science” is not much different than Rachel Carson’s “science” in the book she wrote: Silent Spring.
Bad “science” leads to a hoodwinked public and terrible policy that resulted in millions of human casualties..

“Global CO2 emissions had grown at a rate of 2.9 percent per year between 2000 and 2011, but had slowed to a near-zero growth rate by 2015. They credited drops in CO2 emissions from the United States and China as the primary drivers of the trend.”
=====================
Huh,,,what???

The US had a considerable reduction in emissions thanks to natural gas being so much cheaper than coal because of fracking, which the greens want to outlaw.

But China??? They had no drop in emissions, their emission GROWTH has slowed somewhat but that’s all.

They need to carefully identify the precursors for what happens in 2050 and tell us how we’re looking at 2020, 2025, 2030, etc to see if we’re on track for the 2050 catastrophe. It is 2017 and it does not appear enough bad stuff has happened since 2010 to make me worry. If we don’t start checking off some precursor boxes soon somebody is going to think this is all a big hoax. (Understated intentionally)

OT , news from the once great land down under , Government has just passed legislation banning two stroke motor powered equipment from 1st of July 2019 .
This will help stop the ice from melting at the poles and reduce our carbon footprint for sure .

I’d say they reveal a lot about how dysfunctional their thinking is with the ‘airplane’ example.

Early aircraft had, instead of a 20% chance of crashing, probably had only a 20% chance of getting where they wanted/expected to get.

Yet aeroplanes became uproariously popular.

Somehow I’m reminded of:
“I know an old lady who swallowed a fly……”
and who finished up swallowing a horse.

In case she died of course. And so she did.
Swallowing flies is no big deal. (although some warmists/greenies actually imagine it may be a cure to our woes)
But as we’re seeing with e.g South Australia’s energy fail, CAFE cars and Greenfell Tower – the cure is killing the patient – not the original ailment.

1- the fanatics have hijacked the adjective “dangerous” into a meaningless term.
2- the fanatics have, as we have seen in Australia, corrupted the measurements so that it is clear what temperatures are doing.
3- the fanatics have ignored the reality that nothing dangerous is changing in climate, and are seem quite confused about the difference between weather and climate.

This reminds me of Greg Craven (remember him?), and his moronic “what’s the worst that could happen” grid. Using that “logic”, everything we do, including getting out of bed is a potential “threat”. I mean, what if there really are space aliens preparing to attack and take over our planet? What if the scenario in The Day After Tomorrow happened, all because we refused to stop buring fossil fuels? What if, what if what if….

“A temperature increase greater than 3°C (5.4°F) could lead to what the researchers term “catastrophic” effects, and an increase greater than 5°C (9°F) could lead to “unknown” consequences which they describe as beyond catastrophic including potentially existential threats.”

I’m not sure what’s silliest — the idea that +1.5C from (not really) “pre-industrial” global mean anomaly is “dangerous”, that +3.0C would be “catastrophic”, or that +5.0C would be “existential”. There’s no science to support that, and the utter lack of demonstrated harm from the ~1.0C rise from arbitrary-not-really-pre-industrial levels that’s already happened is striking.